Packaging machine



Jan. 7, 1964 P. A. VAN DE BlLT 3,116,681

PACKAGING MACHINE 9 Sheets-Sheet 1 Filed May 18. 1961 INVENTOR /ETEK 4mm 00s 1444 06 Bar dark/MM ATTORNEY 1964 P. A. VAN DE "BILT 3,116,681

PACKAGING MACHINE Filed May 18. 1961 9 Sheets-Sheet 2 INVENTOR P/ETEE Amvaz 00.: Z4 0: 5/4 7 ATTORNEY Jan. 7, 1964 P. A. VAN DE BILT 3,116,581

PACKAGING MACHINE Filed May 18, 1961 '9 Sheets-Sheet 5 INVENTOR P/ETEA A m moo: VA/V a: 6/

ATTORNEY Jan. 7, 1964 P. A. VAN DE BlLT PACKAGING MACHINE 9 Sheets-Sheet 4 Filed May 18. 1961 INVENT OR P/HE/e lm/owus I A/V DE B/Lr ATTORNEY Jan. 7, 1964 P. A. VAN DE BlLT 3,116,681

PACKAGING MACHINE Filed May 18, 1961 9 Sheets-Sheet 5 INVENTOR H575? ARA/emu: Mm 0 Z5/LT BY Jun; 11%

ATTORNEY Jan. 7, 1964 P. A. VAN DE BlLT PACKAGING MACHINE 9 Sheets-Sheet 6 Filed May 18. 1961 m a m W552;

INVENT OR /ETEA Ak/vowus V4 .05 6/0 BY L74 ATTORNEY Jan. 7, 19 64 P. A. VAN DE BlLT PACKAGING MACHINE 9 Sheets-Sheet 7 Filed May 18. 1961 Q0 /llI||| l |||||l no W W0 m w l lwl- 3 1 mw E g g 8 d e Ihilhl IIwIIL F INVENTOR ATTORNEY 1964 P. A. VAN DE BlLT 7 3,116,681

PACKAGING MACHINE 9 Sheets-Sheet 8 Filed May 18. 1961 INVENTOR 1 /575,? AKA/0.4005 VA/Y 0E B/Lr BY 6% dm ATTORNEY Jan. 7, 1964 Filed May 18. 1961 P. A. VAN DE BlLT 3, 8

PACKAGING MACHINE 9 Sheets-Sheet 9 INVENTOR. P/Hm 4/01/0100: KWMfi/J MW MM ATTORNEY United States Patent l 3,116,681 PACKAGING MACHINE Pieter Arnoldus van de Bilt, Maartensdijk, Netherlands, assignor to N.V. Metaverpa, Maartensdijk, Netherlands, a corporation of Dutch law Filed May 18, 1961, Ser. No. 111,073 3 Claims. (Cl. 10026) The invention relates to a packaging machine in which packaging wire from a supply roll is passed around the package by pressure rollers via a guide until the end is stopped by a clamp, the wire is drawn and subsequently tightened by another clamp, upon which the ends of the Wire are tied together and the cutting off of the wire takes place. Packaging machines of this kind are universally known and have a very complicated driving mechanism, in particular when the machine operates automatically. In fact, the drive of the various parts of the machine is obtained by means of an elaborate transmission system with gear wheels, cams, couplings, and levers, with which the successive operations of the machine are controlled. This entire mechanism is driven by an electric motor. Apart from the complicated character of this mechanism, it has the disadvantage of requiring a good deal of space. In addition, however, there is the much more serious drawback due to the inertia of the moving parts, which inertia begins to play a part whenever anything goes wrong in some part of the machine, e.g. because the wire breaks, gets stuck, leaves the guide or is not gripped properly by a clamp or in the twisting mechanism. Because in such a case the parts of the mechanism that are moving will irrevocably continue to move, one or more vital parts will be damaged. Sudden jerks on the wire to be fed may also occur, which give rise to an undesirable acceleration of the supply roll, in consequence of which the wire unrolls too far or breaks when the supply roll gets stuck, while the wire may also slip between the feeding rollers and thus be damaged.

Now the invention has for its object to simplify such a machine considerably and to eliminate the disadvantages resulting from the inertia of the moving parts.

This object is attained according to the invention by the fact that each of the various operations to be performed by the machine is carried out by a separate pneumatic device. Pneumatic devices have the advantage of having only a small moving mass, which can at once be arrested if this should be necessary, while in such a case only the pressure in the pneumatic device rises, which may result in a gradual overcoming of the resistance and, if this proves impossible, at any rate prevents damage because the machine is stopped. Indeed, the air pressure alone is never capable of damaging the various metal parts of the machine. The small mass of the moving parts presents the additional advantage that the wire can be fed and tightened at a considerably higher rate, which speeds up the machine. Further it is very simple to couple these pneumatic devices with each other in such a Way that a subsequent device comes into operation dependent on the increase or decrease of the pressure in a preceding device, e.g. via pressure contacts, electromagnetically operated valves, spring-loaded valves, and the like, so that the entire mechanism is formed by a minimum number of parts, which are coupled with each other via electric leads and pneumatic pipes, and the movements of which are only slight. Where pneumatic cylinders are used, standardized types can be taken, which implies a considerable simplification of manufacture and repair.

One of the chief sources of difiiculties in the known machines is the device by means of which the wire is 3,116,681 Patented Jan. 7, 1964- ICC taken off the supply roll and passed around the package in the machine, until the end is held in a clamp. This wire may get stuck in many places, especially in the guide. The conventional mechanical driving mechanisms will then tend to move on, which is of course a disadvantage.

In accordance with the invention the drive of the pressure rollers, which convey the wire during the feed, may take place with the aid of a plunger motor. Such a motor may engage one of the pressure rollers almost directly and drive it at great speed. If resistance occurs, the number of revolutions decreases and the pressure increases, so that the resistance is gradually overcome. If the wire strikes against something, the plunger motor due to its small mass can stop at once; the air pressure then building up in the motor will never be able to damage or even only to bend the wire when it has got stuck. It is to be preferred to use for the plunger motor a swash plate motor, because this has a very small moving mass and occupies little space.

When the plunger motor is made reversible, it can serve at the same time to retract the wire. The signal for this can be given by the clamp, which has to intercept the free end of the wire. The direction of rotation of the pressure rollers then reverses, and the wire is pulled from the guide and passed around the package. At the end of this movement the plunger motor will stop due to the increase of the resistance, and according to the invention the drop of the pressure in the outlet of the 'motor is now utilized as a signal for actuating a pneumatic cylinder, which brings into operation the tightening mechanism engaging the wire with a clamp. The drop of the pressure is to be preferred, because this is always constant and a premature signal is avoided, which might be given if use were made of the rise of the pressure, since upon the reversal of the direction of rotation of the plunger motor, for instance, a pressure impulse already arises in the outlet.

The pressure in the tightening cylinder, which rises at the end of the tightening movement, can be used in turn to actuate the clamp which holds the tightened wire and the twisting or other tying mechanism.

The present invention is a continuation-in-part of Ser. Nos. 54,121; 54,122 and 54,123 which were filed September 6, 1960, and are now respectively Patents Nos. 3,060,840; 3,060,841 and 3,060,839. The present application is also copending with Ser. Nos. 69,491 and 69,492 both filed November 15, 1960, the latter being Patent No. 3,081,957.

The invention will now be explained more fully with reference to the drawings.

FIGURE 1 is a plan of the greater part of a packaging machine, the working surface carrying the packages being omitted and the vertical parts of the guide for the wire being shown in cross-section.

FIGURE 2 is a side elevation, certain lateral lining elements being omitted in order to show clearly the interior of the machine.

FIGURE 3 is a cross-section along the line IIIIII in FIGURE 1, in which the feeding and tightening mechanism, which due to lack of space is not shown in FIGURE 1, is also indicated.

FIGURES 4 and 5 are partially cut-away front elevations of the feeding and tightening mechanism of the machine, the tightening mechanism being shown in two diiferent positions.

FIGURE 6 is a plan of the part of the machine shown in FIGURES 4 and 5.

FIGURE 7 is a side elevation of the part of the machine shown in FIGURES 4 and 5.

FIGURE 8 contains the diagram by means of which the pneumatic operation will be explained.

FIGURE 9 is a diagram of the electric circuit.

FIGURE 10 is a side elevational view of a clamp of the machine.

The machine shown in the drawings consists of the frame 1 composed of angle bars or the like, the working surface carrying the packages being omitted everywhere for the sake of greater clearness. This frame comprises an essentially U-shaped longitudinal guide for various parts to be discussed below, which longitudinal guide is formed by the plates 2 and 3 and horizontal guiding tracks 4 and 5 respectively.

Transverse to the main frame 1 and substantially rising above it is the wire-guiding frame 6, with the aid of which the wire is passed around the package. To the right of the wire-guiding frame (FIGURE 3) there is a portion 7 of the frame which projects outside the main frame, and it is here that the feed of the packaging wire takes place via the guide 8, the clamp carrier 9, and the feeding rollers 10 and 11, of which the roller 11 serves to keep the wire firmly in contact with the toothed roller 10. The wire is then conducted into the guiding channel 12 (FIGURE 1) of the lower bar of the guiding frame, passes through the tying and cutting mechanism located between the plates 2 and 3, and subsequently passes through the guiding channel of the further part of the lower bar and next through the other parts of the guiding frame, first vertically upwards, then horizontally back and vertically downwards again, the end of the wire ultimately passing through a channel extending parallel to the channel 12 and ending behind the space for the tying mechanism in a clamp 13.

The drive of the feeding roller 10 takes place with the aid of a plunger motor 14 (see FIGURES 6 and 7), which motor, as is quite clear from the drawing, is extremely small and to which are connected inlet and outlet pipes for compressed air, not shown in the drawings. Motor 14 is similar to that described in U.S. Patent No. 1,781,133.

The clamp 13 is mounted so as to be slightly movable, and by this movement a switch is controlled, which provides in a way to be explained presently for the clamp 13 to be closed and the direction of rotation of the plunger motor 14 to be reversed, so that the packaging wire, which has been passed around the package via the guiding tracks, can be laid closely about the package. Clamp 13 as shown more clearly in FIGURE 10 includes a flat upper jaw member 117 and an upwardly movable round member 118 which is pivotally mounted by a pivot pin (not shown) adjacent the peripheral edge thereof. A sliding member 119 has a pin 120 at its upper end engaging an opening in member 118 adjacent the peripheral edge thereof opposite the above mentioned pivot pin. The sliding member 119 is actuated by the connecting rod 120 via the bell crank member 120' pivotally mounted on the body portion 13 of clamp 13. The rod 120 is connected to a piston in the pneumatic cylinder 36 which reciprocates rod 120. Clamp 13 is mounted on the end of a rod 121 which is supported in hearings in the member 122 fastened to plate 2. Rod 121 is adapted to reciprocate and move against the action of spring 123. The end of rod 121 near the clamp 13 is flat, and this fiat portion 124 is acted upon by a leaf spring 125 which is mounted on plate member 126 which in turn is mounted on plate 2. The leaf spring 125 by cooperating with the flat surface 124 constantly tends to maintain clamp 13 in its vertical center position of rest. Clamp 13 in its position of rest abuts against one side of fixed plate 127 while on the other side thereof rests a guiding block 128 containing guiding channel 12. A biasing means 129 maintains guiding block 128 against plate 127. A

more complete disclosure and operation of clamp 13 is set forth in applicants U.S. Patent No. 3,060,839. The switch 15 can also cause a number of small pneumatic cylinders 16 to provide for the opening of the guiding track for the wire, so that the latter can easily be laid round the package. When at the end of the movement of retracting the wire the latter has been applied round the package, the plunger motor 14 stops, and next, dependent on the drop of the pressure in its outlet pipe, the tightening mechanism 9 is actuated by the supply of compressed air to the pneumatic cylinder 17 (see FIGURE 3). Tightening mechanism 9 includes a main lever 109 pivotally connected at 110 to frame 1. Guide 8 is mounted on main lever 109 and as can be seen the wire W is passed through guide 8 to feeding rollers 10 and 11. A slot is provided in main lever 109 in which clamp 19 is movably mounted between guide members 111, 112. A double-armed lever 20 is pivotally mounted in the slot and includes one arm 20' engaging a recess in clamp 19 while the other arm 20" engages a recess in an extension 18. Guide member 112 and the inner end of the slot form a channel in which extension 18 is reciprocably movable and an abutment against which arm 20" abuts when extension 18' is moved to the right in FIG. 4. Rod 18 and extension 18 are pivotally connected to a secondary lever 113 which is pivotally connected to main lever 109 at 114. A spring 115 is connected between secondary lever 113 and plate 116 on which cylinder 17 is mounted. Spring 115 maintains tightening mechanism 9 in a normally inoperative position. Extension 18' has a head element 18" which abuts against lever 109 as shown in FIG. 4 to maintain levers 109 and 113 in connection with each other when the tightening mechanism is in the inoperative position. As appears from FIGURE 4, the piston rod 18 of the cylinder 17 controls the clamp 19 of the clamp carrier 9 because the rod 18 moves to the right and thus forces the clamp 19 upwards by means of the extension 18' and double-armed lever 20. After the clamp 19 has been closed, the rod 18 moves the whole clamping mechanism to the right, as shown in FIGURE 5, as a result of which the Wire is tightened firmly about the package. At the end of the tightening movement the pressure in the cylinder 17 will rise until a given adjustable value has been reached, and this pressure is now utilized to actuate a clamp 75' which is located between the feeding rollers and the tying mechanism and serves to hold the end of the wire that has just been tightened, with a view to enabling the clamp carrier to return to its initial position, and also to actuate the twisting mechanism, by means of which the ends of the wire are tied together. This twisting mechanism is formed by a twisting pinion 21, which is located in a block 22 adapted to move on the guiding tracks 4, which block can be moved to and fro by the pneumatic cylinder 23, which is coupled with the block 22 via the rod 24. By a movement to the left of the block 22 in FIGURE 2 the juxtaposed ends of the wire are fed to the twisting pinion, which twisting pinion is subsequently rotated by the gear wheel 25, which is driven by the toothed rack 26, which in turn is driven by the pneumatic cylinder 27. The correct sequence of these movements is controlled by the switches 28, 29, 30, and 31, as will be described in greater detail. To this end the toothed rack is equipped with an abutting surface 32 and an extension 33, while the rod 24 has a cross-arm, which cooperates with the switches 29 and 30. During the return movement of the toothed rack 26 the wire is cut off via the lever 34, which moves the knife lever 35.

After the ends of the wire have been cut off, the cylinder 36, which served to tighten the clamp 13, is actuated in the reverse sense, in consequence of which in the first place the clamp 13 is released and is subsequently moved to the left in FIGURE 1, so that the cut-off end of the wire may drop out.

From the above it appears that the operations to be performed by the machine are brought about with the aid of a plunger motor and a comparatively small number of pneumatic cylinders. These require only little space and have only small moving masses. A further advantage of the pneumatic drive is that the exhaust air can be utilized for cleaning particular parts of the machine which tend to foul, while a lubricating and protective effect can be obtained if the air previously passes through an oil-spray lubricating device.

The invention will now be explained more fully with reference to a diagram which shows the pneumatic and the electric circuit.

The diagram shown in FIGURE 8 comprises the pneumatic circuit with the electromagnetically operated valves and the pneumatically operated switch-over valves, and FIGURE 9 comprises the electric circuit, so that electromagnetic valves and switches appearing in FIGURE 9 as well as FIGURE 8 are denoted by identical numerals. The main supply of compressed air takes place via the pipe 40, filter 41, reducing device 42, and oil-spray lubricating device 43. In the FIGURE 8 diagram the unbroken lines denote those pipes in which the air is compressed and the broken lines those in which no pressure is present in the position of the diagram at the moment. The diagram has been drawn for the position in which the motor 14 feeds the wire with the aid of the rollers 10 and 11. The motor 14 therefore receives air via the pipe 44, the branch 45, the valve 46, and the pipe 47. The discharge of air from the motor takes place via the pipe 48 and the exhaust opening of the switch-over valve 49.

When the wire has been passed all around, the end of it is gripped by the clamp 13 (see FIGURE 1), the operating cylinder 50 of which clamp is shown in the neutral position. This clamp is adapted to pivot in the direction of movement of the wire, so that the wire gripped by the clamp will tip over said clamp, in consequence of which the contact 51 in the switch-box is closed. The machine is now in its initial position for performing the next complete cycle, and when the starting switch 52 is now closed, which may, for instance, be efiected by a package being fed to the machine, the supply of current to the electromagnetic valve 53 is brought about, in consequence of which this valve switches over and the pipe 54 receives compressed air. By this means the valve 49 is switched over via 55, but so is the valve 56, in consequence of which the pipe 57 receives compressed air from the main pipe 44, which pipe leads to the cylinder 50 of the clamp 13, in consequence of which said clamp is closed and holds the end of the wire, while at the same time from the pipe 57 a branch may lead to a number of cylinders 16 for opening the guide for the wire.

The switch-over of the valve 49 has resulted in that the exhaust pipe 48 has now received compressed air from the main pipe 44, but the motor 14 is not yet at once able to reverse its direction of rotation, since compressed air is still present in the pipe 47. The pressure produced in the pipe 57 by the switch-over of the valve 56 now acts via the pipe 58 on the valve 46, which, however, does not switch over until the pipes 59 and 60 have been sufliciently exhausted via valve 49, when the pipe 47 begins to exhaust, so that the pressure in the pipe 48 begins to predominate, and the motor 14 reverses its direction of rotation, which reversal is used to draw the wire tighter about the package. At the end of this movement the pressure in the outlet pipe 47 will fall, and this fall of the pressure is measured by the plunger 61, which is loaded by the spring 62 and which closes the contact 63 when the fall of the pressure is suflicient. This closing of the contact 63 implies the excitation of the electromagnetic valve 64, in consequence of which the latter switches over and from the mainr pipe 44 compressed air is supplied to the pipe ich leads t'o the cylinder 17 of the tightening mechhe=-wire is now tightened firmly about the hilejhe pressure in the cylinder 17 rises, and this ris f the pressure is measured via the pipe 66 by the measuring device 67, which is equipped with a plunger sliding against spring tension. When a given pressure has been reached, this measuring device closes the switch 68,

which is provided with a magnet coil which has been incorporated in such a way in the electric circuit that through the mechanical closing of the switch 68 the latter is held in its closed position. The closing of the switch 68 results in the excitation of the electromagnetic valve 69, in consequence of which compressed air is supplied from the main pipe 44 via the pipes 70 and 71 to the switch-over valve 72. Thus the pipes 73 and 74 receive compressed air, with the result that the cylinder 75 for controlling the clamp 75' which is to hold the tightened end of the wire is brought into operation, while further the cylinder 23 for moving the twisting mechanism is operated. Owing to the displacement of the twisting block by the cylinder 23 the contact 29 is broken and the contact 3%) closed. The breaking of the contact 29 involves at the same time the neutralization of the excitation of the electromagnetic valve 76 and of the electromagnetic valve 64. The adjustment of the valve 76 breaks the connection between the switch-over valves 46 and 49, which at this moment is still of no account. By the neutralization of the excitaiton of the valve 64, the pipes 65, 66 and the cylinder 17 can be exhausted, in consequence of which the tightening mechanism 9 returns to its initial position under the influence of a spring.

Owing to the closing of the contact 30 the electromagnetic valve 77 is excited, in consequence of which via the pipe 78 compressed air is supplied to the valve 49, which switches over owing to this, while at the same time via the pipe 79 compressed air is supplied to the switch-over valve 89, owing to which the latter switches over and compresed air can now be supplied from the main pipe to the cylinder 27, which serves to displace the toothed rack 26 by means of which the twisting pinion 21 is rotated. This displacement of the toothed-rack results in the breaking of the contact 81 and the closing of the contact 82 in the switch-box 31, and at the end of its movement in the closing of the contact 28. The breaking of the contact 81 results in the neutralization of the excitation of the switch 68, in consequence of which the latter opens again, and this in turn results in reversal of the electromagnetic valve 69, by which means the pipes leading to the valves 49 and are exhausted. At first the closing of the contact 82 has no consequence at all. The closing of the contact 82 merely implies that a part of the circuit of the electromagnetic valve 83 is closed, which valve, however, cannot yet be excited, because the contact 84 in the switch-box 15, which is controlled by the clamp 13, is still open.

At the end of the movement of the toothed rack the contact 28 is closed, and this implies excitation of the ele tromagnetic valve 85, in consequence of which the valve 80 is reversed by supply of compressed air from the main pipe and the drive of the toothed rack is reversed. During the return movement of the toothed rack (see FIG- URE 2) the cutting mechanism for the wires is operated, owing to which the clamp 13 is released and thus closes the contact 84. This in turn results in the closing of the circuit of the electromagnetic valve 83, owing to which the latter switches over and compressed air is supplied from the main pipe 44 to the pipes 86 and 87. The pipe 87 leads to the pneumatic cylinder 50 for operating the clamp 13, in consequence of which the latter opens and is forced away until the cut-ofi? end of the wire can drop out. The pressure in the pipe 86 results in switch-over of the valve 72, owing to which the twisting mechanism returns to its initial position and the cylinder 75 also releases the clamp holding the Wire. When the toothed rack and the twisting mechanism have returned to their initial position, the contacts 81 and 29 are closed again and the contact 82 is broken, while the valve 76 is reexcited, so that via the previously reversed valve 49 compressed air is supplied to the valve 46, which reverses, so that via the main pipe compressed air is supplied again to the pipe 47, which actuates the motor 14 for feeding wire again. As soon as the end of the latter reaches the clamp 13, the contact 51 is closed again and the next cycle has become dependent on the operation of the starting switch 52 once more.

The diagram finally includes the pipe 88, by means of which compressed air is constantly supplied to the cylinder 89, with which the pressure roller 11 is kept under pressure. Further a switch 90 is present, which scans the feed of the wire and breaks the contact as soon as the wire has run out, so that the valve 76 after the return of the twisting mechanism cannot be excited, which prevents the air motor feeding an insufiicient remnant of the wire supply into the machine. The current supply is controlled by the connection to the mains at 91, while at 92 is shown a reversing switch, by means of which the machine can be returned to its initial position when in the middle of a cycle something has gone wrong and the machine has come to a standstill.

It is further observed that the clamp 13' is returned to the initial position by the opening of the contact 82 at the end of the path traversed by the toothed rack during its return movement. The electromagnetic valve 83 then returns to its initial position, in consequence of which the cylinder 50 is exhausted again and is able to return to its neutral position.

I claim:

1. A wire tying packaging machine having a working surface to support packages to be tied, a wire guiding and looping frame of loop formation having wire receiving slot means therein opening at the inner peripheral portion of the frame, said slot means having a receiving end and a terminating end, feed roller means disposed adjacent said frame for longitudinally feeding a wire into the receiving end of the slot means in the frame to form a loop therein, a reversible pneumatic plunger motor driving the roller means, said slot means being entirely free of switches and obstructions throughout its length, a tiltable clamp located at the terminating end of the slot means and adapted to receive the leading end of the wire and to be tilted thereby, a switch mounted on said frame adjacent to but spaced from said clamp, said switch being operated by said clamp upon tilting thereof, means operated by said switch for controlling the closure of the clamp as well as the reversal of the pneumatic motor to withdraw the wire from the slot means to surround a package and tighten same therearound, and tying and cutting means disposed adjacent said clamp to tie and cut the wire.

2. A wire tying packaging machine having a working surface to support packages to be tied, a wire guiding and looping frame of loop formation having wire receiving slot means therein opening at the inner peripheral portion of the frame, said slot means having a receiving end and a terminating end, feed roller means disposed adjacent said frame for longitudinally feeding a wire into the receiving end of the slot means in the frame to form a loop therein, a reversible pneumatic plunger motor driving the roller means, said slot means being entirely free of switches and obstructions throughout its length, a tiltable clamp located at the terminating end of the slot means and adapted to receive the leading end of the wire and to be tilted thereby, a switch mounted on said frame adjacent to but spaced from said clamp, said switch being operated by said clamp upon tilting thereof, means operated by said switch for controlling the closure of the clamp as well as the reversal of the pneumatic motor to withdraw the wire from the slot means to surround a package and tying and cutting means disposed adjacent said clamp to tie and cut the wire, said plunger motor having an exhaust pipe, a second clamp for gripping the wire disposed adjacent said plunger motor, and means, responsive to a pressure drop in said exhaust pipe during the reversed movement to withdraw the wire from the slot means in the frame, to actuate the second clamp to grip the wire and to tension it about a package.

3. A wire tying packaging machine having a working surface to support packages to be tied, a wire guiding and looping frame of loop formation having wire receiving slot means therein opening at the inner peripheral portion of the frame, said slot means having a receiving end and a terminating end, feed roller means disposed adjacent said frame for longitudinally feeding a wire into the receiving end of the slot means in the frame to form a loop therein, a reversible pneumatic plunger motor driving the roller means, said slot means being entirely free of switches and obstructions throughout its length, a tiltable clamp located at the terminating end of the slot means and adapted to receive the leading end of the wire and to be tilted thereby, a switch mounted on said frame adjacent to but spaced from said clamp, said switch being operated by said clamp upon tilting thereof, means operated by said switch for controlling the closure of the clamp as well as the reversal of the pneumatic motor to withdraw the wire from the slot means to surround a package, said plunger motor having an exhaust pipe, a second clamp for gripping the wire disposed adjacent said plunger motor, means, responsive to a pressure drop in said exhaust pipe during the reversed movement to withdraw the wire from the slot means in the frame, to actuate the second clamp to grip the wire and to tension it about a package, the means for tensioning the wire comprising a pneumatic cylinder, said wire being fed into the frame to form a loop in which the free leading end portion of the wire overlaps another portion of the wire in the loop, means to tie the overlapping portions of the wire and to cut the wire loop from a supply, pneumatic means operating said tying and cutting means, connecting means interconnecting said pneumatic means and said pneumatic cylinder, and switch means operatively connected to the pneumatic cylinder of the wire tensioning means and controlled thereby to operate said pneumatic means.

References Cited in the file of this patent UNITED STATES PATENTS 2,831,422 Black et al. Apr. 22, 1958 2,908,215 Fawcett Oct. 13, 1959 2,908,216 Brouse et a1 Oct. 13, 1959 3,012,497 Fryer Dec. 12, 1961 

1. A WIRE TYING PACKAGING MACHINE HAVING A WORKING SURFACE TO SUPPORT PACKAGES TO BE TIED, A WIRE GUIDING AND LOOPING FRAME OF LOOP FORMATION HAVING WIRE RECEIVING SLOT MEANS THEREIN OPENING AT THE INNER PERIPHERAL PORTION OF THE FRAME, SAID SLOT MEANS HAVING A RECEIVING END AND A TERMINATING END, FEED ROLLER MEANS DISPOSED ADJACENT SAID FRAME FOR LONGITUDINALLY FEEDING A WIRE INTO THE RECEIVING END OF THE SLOT MEANS IN THE FRAME TO FORM A LOOP THEREIN, A REVERSIBLE PNEUMATIC PLUNGER MOTOR DRIVING THE ROLLER MEANS, SAID SLOT MEANS BEING ENTIRELY FREE OF SWITCHES AND OBSTRUCTIONS THROUGHOUT ITS LENGTH, A TILTABLE CLAMP LOCATED AT THE TERMINATING END OF THE SLOT MEANS AND ADAPTED TO RECEIVE THE LEADING END OF THE WIRE AND TO BE TILTED THEREBY, A SWITCH MOUNTED ON SAID FRAME ADJACENT TO BUT SPACED FROM SAID CLAMP, SAID SWITCH BEING OPERATED BY SAID CLAMP UPON TILTING THEREOF, MEANS OPERATED BY SAID SWITCH FOR CONTROLLING THE CLOSURE OF THE CLAMP AS WELL AS THE REVERSAL OF THE PNEUMATIC MOTOR TO WITHDRAW THE WIRE FROM THE SLOT MEANS TO SURROUND A PACKAGE AND TIGHTEN SAME THEREAROUND, AND TYING AND CUTTING MEANS DISPOSED ADJACENT SAID CLAMP TO TIE AND CUT THE WIRE. 